A multiple reaction monitoring (MRM) measurement using a liquid chromatograph mass spectrometer (LC-MS) which includes the combination of a liquid chromatograph and a tandem quadrupole mass spectrometer has been frequently used for quantitative analyses of low-molecular compounds, such as drugs or agricultural chemicals. In an MRM measurement, influences of foreign components can be removed by two-stage mass separators (quadrupole mass filters). Therefore, a quantitative analysis of a target component can be performed with high accuracy even in the case where there is a foreign component having a retention time close to that of the target component and the two components cannot be sufficiently separated from each other in the liquid chromatograph. Furthermore, in an MRM measurement using an LC-MS, it is normally possible to set a plurality of combinations of precursor ion and product ion (which are generally called “MRM transitions”) within one measurement time range, allowing for a quantitative determination of several tens of kinds of components or even a hundred and several tens of kinds of components by a single measurement. Such an analytical technique is called the “simultaneous multicomponent analysis”. In recent years, this technique has been widely used for the testing of residual agricultural chemicals, testing of contaminants in environmental water, and other purposes.
On the other hand, for quantitative analyses of high-molecular compounds, such as sugar chains or glycopeptides, liquid chromatographs employing an ultraviolet absorption detector or fluorescent detector as the detector are still frequently used (for example, see Non Patent Literature 1 or 2). One of the reasons is as follows: In LC-MS, ion sources which employ electrospray ionization (ESI) or similar methods are commonly used. If a high-molecular compound, such as a sugar chain or glycopeptide, is ionized by such an ion source, a plurality of kinds of multivalent ions whose valency is not one are easily generated. Accordingly, unlike the case of the low-molecular compounds, the simple combination of one precursor ion and one product ion cannot always be obtained for each component. There is also another problem. i.e. as is commonly known, sugar chains have non-uniformity in structure, which causes the detected ionic valencies to considerably vary depending on the sample. Due to these problems, unlike the quantitative analysis of a low-molecular compound, it is difficult to perform a simultaneous multicomponent analysis using an LC-MS in the case of a quantitative analysis of a high-molecular compound, such as a sugar chain or glycopeptide. Consequently, it is necessary to perform a quantitative analysis for each individual compound using a liquid chromatograph which employs an ultraviolet absorption detector or fluorescent detector as the detector. Such an analysis is low in throughput. Thus, a reduction in the time and labor necessary for the analysis has been a major challenge.